1. 北京大学空间信息集成与3S工程应用北京市重点实验室，北京 100871
2. College of Engineering, South Dakota State University, Brookings, SD 57007, USA
Analyses of Land Surface Emissivity Characteristics in Mid-Infrared Bands
ZHAO Shuai-yang1, HU Xing-bang1, JING Xin2, JIANG Si-jia1, HE Li-qin1, MA Ai-nai1, YAN Lei1*
1. Beijing Key Lab of Spatial Information Integration & 3S Application, Peking University, Beijing 100871，China
2. College of Engineering, South Dakota State University, Brookings, SD 57007, USA
Abstract：Land surface temperature (LST) plays an important role in the process of ground-air interaction and is an parameter in global change research. At the same time, the emissivity of land surface is the key input parameter of LST inversion. Mid-infrared spectrum (3~5 μm) is between visible-near infrared (0.38~2.5 μm) and thermal infrared spectrum (8~14 μm). The emissivities of terrestrial materials exhibit unique characteristics in mid-infrared spectrum, which can be used for frost monitoring and mineral composition analysis et al. Energy detected with sensor in the mid-infrared region, however, is a combination of emitted radiation from terrestrial materials and reflected radiation due to sun irradiance. The energy separation mechanism of these two parts is complicated. Therefore, there are few relevant literatures about researches on emissivities of terrestrial materials in mid-infrared spectrum. In this paper, the effective emissivities of MODIS infrared channels were calculated for a single uniform surface and a complex region with mixed pixel. It is found that the effect of surface temperature is insignificant for effective emissivity calculation in a single uniform surface. Under complex surface, the effective emissivity has a coupling effect with composition ratio of materials in the mixed pixel and surface temperatures of these materials. Within the allowable range of error, the effective emissivity of mixed pixel can ignore the effect of materials’ surface temperature. The sensitivity of emissivity error to the precision of LST inversion varies with wavelength. An accuracy of 1 K in LST retrieval requires emissivity error be constrained to within 0.04 in mid-infrared region, while within 0.02 in thermal infrared region. It can be seen that mid-infrared spectrum has much potentials in LST retrieval.
Key words：Mid-infrared; Emissivity; Land surface temperature; MODIS; Broad spectrum
赵帅阳，胡兴帮，景 欣，蒋思佳，贺丽琴，马蔼乃，晏 磊. 中红外波段地表发射率特性分析[J]. 光谱学与光谱分析, 2018, 38(05): 1393-1399.
ZHAO Shuai-yang, HU Xing-bang, JING Xin, JIANG Si-jia, HE Li-qin, MA Ai-nai, YAN Lei. Analyses of Land Surface Emissivity Characteristics in Mid-Infrared Bands. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(05): 1393-1399.
[1] Serafini Y V. International Journal of Remote Sensing, 1987, 8(10): 1547.
[2] JING Xin, HU Xiu-qing, ZHAO Shuai-yang, et al(景 欣, 胡秀清, 赵帅阳，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2017, 37(2): 394.
[3] MA Wen-po(马文坡). Infrared & Laser Engineering(红外与激光工程), 2014, 43(12): 3861.
[4] Mushkin A, Balick L K, Gillespie A R. Remote Sensing of Environment, 2005, 98(2-3): 141.
[5] Salisbury John W, Dana M D’Aria. Remote Sensing of Environment, 1994, 47(3): 345.
[6] Li Zhaoliang, Petitcolin F, Zhang Renhua. Science in China Series E: Technological Sciences, 2000, 43(S1): 23.
[7] Gillespie A, Rokugawa S, Matsunaga T, et al. IEEE Transactions on Geoscience and Remote Sensing, 1998, 36(4): 1113.
[8] Li Zhaoliang, Francois Becker. Remote Sensing of Environment, 1993, 43(1): 67.
[9] Salomonson V V, Barnes W L, Maymon P W, et al. IEEE Transactions on Geoscience and Remote Sensing, 1989, 27(2): 145.
[10] King M D, Kaufman Y J, Menzel W P, et al. IEEE Transactions on Geoscience and Remote Sensing, 1992, 30(1): 2.
[11] Running S W, Justice C O, Salomonson V, et al. International Journal of Remote Sensing, 1994, 15(17): 3587.
[12] Baldridge A M, Hook S J, Grove C I, et al. Remote Sensing of Environment, 2009, 113(4): 711.
[13] Wan Z, Dozier J. IEEE Transactions on Geoscience & Remote Sensing, 1996, 34(4): 892.
